I support this if in the sections of Introductions/Farewells / Goals & Achievements had less of an effect on this rule. There's little to no difference in saying "Welcome" or "Hi welcome." or saying "Congratulations" or "Gz man" - But that extra 2 letters make's a huge difference apparently.
PM'd a few people on the forums who I've noticed only posted one word in their replies and shot them a private message so they could edit their post and add in an extra word so they can avoid being warned for it.
I believe it also comes down on how often a person is using one word replies. If they are going around on every post just simply putting one word for post count, then that should be fair game for a staff member to warn him about it, but if they are just simply replying with one word, because in some cases there's just nothing else more to say, then I believe that should be ok. We're a forum for a RSPS, we don't need super high quality forum replies in every situation, as long as we're enjoying the forum and using it, it shouldn't be a problem.
If "post count farming" is the issue, remove it from the postbit. Or as Code said, it reduces the integrity of people farming their post count already for awards or whatnot, in which I feel like it shouldn't make much of a difference, you can already just spam all the achievements with "gz dude" and all the suggestions with an "I support" No support" reply in which is nearly the same as just a one worded.